binarystore: Add ReadOnly Mode
Add Read Only mode to the binary store. In this mode,
all blobs are not writable, no new blobs can be created and
the storage protobuf can't be modified in any way.
Also added simple API for reading/examining blob store
without modifying it.
Signed-off-by: Maksym Sloyko <maxims@google.com>
Change-Id: I12e3473351be98820d8e5df1b71a6d43699aa671
diff --git a/binarystore.hpp b/binarystore.hpp
index c86934e..f46f69c 100644
--- a/binarystore.hpp
+++ b/binarystore.hpp
@@ -48,6 +48,11 @@
blob_.set_blob_base_id(baseBlobId_);
}
+ BinaryStore(std::unique_ptr<SysFile> file, bool readOnly = false) :
+ readOnly_{readOnly}, file_(std::move(file))
+ {
+ }
+
~BinaryStore() = default;
BinaryStore(const BinaryStore&) = delete;
@@ -60,6 +65,7 @@
bool openOrCreateBlob(const std::string& blobId, uint16_t flags) override;
bool deleteBlob(const std::string& blobId) override;
std::vector<uint8_t> read(uint32_t offset, uint32_t requestedSize) override;
+ std::vector<uint8_t> readBlob(const std::string& blobId) const override;
bool write(uint32_t offset, const std::vector<uint8_t>& data) override;
bool commit() override;
bool close() override;
@@ -76,6 +82,17 @@
createFromConfig(const std::string& baseBlobId,
std::unique_ptr<SysFile> file);
+ /**
+ * Helper factory method to create a BinaryStore instance
+ * This function should be used with existing stores. It reads
+ * the baseBlobId name from the storage.
+ * @param sysFile: system file object for storing binary
+ * @param readOnly: if true, open the store in read only mode
+ * @returns unique_ptr to constructed BinaryStore.
+ */
+ static std::unique_ptr<BinaryStoreInterface>
+ createFromFile(std::unique_ptr<SysFile> file, bool readOnly = true);
+
private:
/* Load the serialized data from sysfile if commit state is dirty.
* Returns False if encountered error when loading */
@@ -84,7 +101,10 @@
std::string baseBlobId_;
binaryblobproto::BinaryBlobBase blob_;
binaryblobproto::BinaryBlob* currentBlob_ = nullptr;
+ /* True if current blob is writable */
bool writable_ = false;
+ /* True if the entire store (not just individual blobs) is read only */
+ bool readOnly_ = false;
std::unique_ptr<SysFile> file_ = nullptr;
CommitState commitState_ = CommitState::Dirty;
};